Water sports, such as wake boarding, commonly require use of a tow bar system to pull a rider on a water recreation device along the surface of the water behind a powerboat. A typical tow bar system includes a tow line and hand grips. Depending on the types and durations of maneuvers a rider wishes to perform, the rider may prefer a tow bar system that employs a more traditional single-grip configuration or, alternatively, that features an individual grip for each hand (e.g., dual grip). Furthermore, to achieve desired performance and/or maximize enjoyment during a single ride, the rider may prefer to selectively alternate between dual-grip and single-grip modes.
However, current tow bar systems can be difficult for a rider (particularly a novice rider) to effectively use. For example, inexpensive single-grip tow bars routinely force the rider's hands together for two-hand gripping while the recreation device is in motion, thereby limiting the rider's ability to physically adjust her grip for comfort, energy-conservation, and/or performance purposes. Furthermore, both the single-grip and dual-grip tow bar systems can be difficult to hold onto during the rider's transition from being pulled out of the water at the start of a ride to being accelerated to planing speed during the course of a ride.
Several dual-grip tow bar systems exist for use by a rider of a water recreation device. For example, a tow line characterized by the provision of two grips, one for each hand of a water skier, is disclosed in U.S. Pat. No. 3,092,068 to Brownson et al. (“Brownson”), U.S. Pat. No. 4,069,786 to La Botz (“La Botz”), U.S. Pat. No. 3,219,007 to Kiefer et al. (“Kiefer”), U.S. Pat. No. 3,304,904 to Spurlock et al. (“Spurlock”), U.S. Pat. No. 4,392,833 to Hayden (“Hayden”), and U.S. Pat. No. 4,867,722 to Joseph (“Joseph”). However, neither the free-standing dual grips shown in the Brownson and La Botz references nor the convertible dual grips described in the Kiefer, Spurlock, Hayden, and Joseph references maintain a substantially fixed orientation in relation to each other when used in dual-grip mode because each grip is mechanically supported only by tow rigging consisting entirely of ropes. These dual-grip designs implemented with loose rigging have some performance advantages, but they compromise rider comfort and energy. Specifically, the skier must rely on muscle strength both to hang on to the grips during the transition from pullout to planing speed, and also to maintain the grips in a functional orientation while being pulled. Such exertion may cause the rider to tire before she can sufficiently enjoy the ride on a recreation device.
To help a rider maintain comfort and conserve energy, releasable towing systems offer, among other advantages, an opportunity for a rider of a water recreation device to passively ride while the tow line is affixed to the board itself, Releasable towing systems for water recreation devices are disclosed in La Botz and also in U.S. Pat. No. 4,989,531 to Humphrey, U.S. Pat. No. 5,083,955 to Echols, and U.S. Pat. No. 5,163,860 to Clark. For example, the La Botz and Humphrey references both describe adding an intermediate hooking mechanism to a conventional tow line that a rider may use to snag an anchor member affixed to a water recreation device for the purpose of towing. Similarly, the Echols reference describes draping from a tow line a coupling device that mates with a retainer mounted on the surface of a water recreation device. However, these systems pose one or both of the following challenges for a rider, and particularly for a novice rider: 1) manipulating a small hooking mechanism to release it from an anchor member while in the process of being towed, and 2) managing the instability of a single-grip or dual-grip tow bar system that is loosely tethered by ropes. Both the Echols and Clark patents disclose presenting a recess in the top surface of a water recreation device to accommodate a tow bar. However, these single-grip tow bars expose the rider's hands to being pinched between the tow bar and the board when the rider attempts to remove the substantially planar tow bar from a low-profile tow hook or from a recess in the board's surface.